What does CASS mean?

As above. It's a service designed to give customers more flexibility in choosing a current account provider. If you're switching from Bank A to Bank B, and both are part of the CASS scheme, then you approach Bank B who will arrange for your account at Bank A to be closed, any balance transferred, standing orders, direct debits and other recurring bills will be carried over, and a redirection service put in place so any payments to your old account are redirected to the new one. That's the process for a full switch - a partial switch is also possible.

MEM62 wrote: »

In my profession, Caro Accounts Settlement Systems

Don’t you mean cargo?:D

https://www.iata.org/services/finance/Pages/cass.aspx